Application of single and mixture of selected natural dyes on cotton fabric: A scientific approach

摘要

Cotton fabric was dyed with four different natural dyes (turmeric, myrobolan, madder, red sandalwood) using pre, post and simultaneous-mordanting techniques. Aluminium sulphate was used as a mordant. Some samples were also dyed with a combination of turmeric with madder or red-sanda/wood and a combination of myrobolan with madder or red sandalwood in different proportions. Selected mordanted and dyed samples were after-treated with a catlonic dye fixing agent. Turmeric being a direct dye type, gave maximum colour strength when applied by the simultaneous-mordanting method, either singly or in combination with other dyes. Turmeric also showed poor wash fastness, which was improved to some extent by after-treatment with a catlonic dye fixing agent and on combination of turmeric with other dyes of better fastness. Combined dye application of turmeric with the other dyes by the simultaneous-mordanting method resulted in a better shade development as the observed colour strength values were always higher than the calculated or the expected values. However, myrobolan on combination with other dyes gave higher colour strength when applied by the post-mordanting method. In the case of the simultaneous-mordanting method, myrobolan did not show a synergistic effect in terms of the observed and calculated K/S values.